Hyperelliptic odd coverings
نویسندگان
چکیده
We investigate a class of odd (ramification) coverings C → ℙ1 where is hyperelliptic, its Weierstrass points map to one fixed point and the covering makes hyperelliptic involution commute with an ℙ1. show that total number minimal degree 4g \(\left({\matrix{{3g} \cr {g - 1} \cr}} \right){2^{2g}}\) when general. Our study approached from three main perspectives: if effective theta characteristic they are described as solution certain differential equations; then studied monodromy viewpoint deformation argument leads final computation.
منابع مشابه
Most Odd Degree Hyperelliptic Curves Have Only One Rational Point
Consider the smooth projective models C of curves y = f(x) with f(x) ∈ Z[x] monic and separable of degree 2g + 1. We prove that for g ≥ 3, a positive fraction of these have only one rational point, the point at infinity. We prove a lower bound on this fraction that tends to 1 as g → ∞. Finally, we show that C(Q) can be algorithmically computed for such a fraction of the curves. The method can b...
متن کاملDeterministic Encoding and Hashing to Odd Hyperelliptic Curves
In this paper we propose a very simple and efficient encoding function from Fq to points of a hyperelliptic curve over Fq of the form H : y = f(x) where f is an odd polynomial. Hyperelliptic curves of this type have been frequently considered in the literature to obtain Jacobians of good order and pairing-friendly curves. Our new encoding is nearly a bijection to the set of Fq-rational points o...
متن کاملClassification of Elliptic/Hyperelliptic Curves with Weak Coverings against the GHS Attack under an Isogeny Condition
The GHS attack is known to map the discrete logarithm problem(DLP) in the Jacobian of a curve C0 defined over the d degree extension kd of a finite field k to the DLP in the Jacobian of a new curve C over k which is a covering curve of C0, then solve the DLP of curves C/k by variations of index calculus algorithms. It is therefore important to know which curve C0/kd is subjected to the GHS atta...
متن کاملElliptic curves with weak coverings over cubic extensions of finite fields with odd characteristic
In this paper, we present a classification of elliptic curves defined over a cubic extension of a finite field with odd characteristic which have coverings over the finite field therefore subjected to the GHS attack. The densities of these weak curves, with hyperelliptic and non-hyperelliptic coverings, are then analyzed respectively. In particular, we show, for elliptic curves defined by Legen...
متن کاملClassification of Elliptic/hyperelliptic Curves with Weak Coverings against GHS Attack without Isogeny Condition
The GHS attack is known as a method to map the discrete logarithm problem(DLP) in the Jacobian of a curve C0 defined over the d degree extension kd of a finite field k to the DLP in the Jacobian of a new curve C over k which is a covering curve of C0. Recently, classification and density analysis were shown for all elliptic and hyperelliptic curves C0/kd of genus 2, 3 which possess (2, . . . , ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Israel Journal of Mathematics
سال: 2022
ISSN: ['1565-8511', '0021-2172']
DOI: https://doi.org/10.1007/s11856-022-2318-2